if the leaves are weak i usually pull them off(its easier that way to me)
i dont think its good to keep dead and dying leaves on and around the plant cause it can help attract pets. if they dont pull off maybe their not ready to be pulled off. if a blade or half a blade is bad and doesnt look repairable get the siccors our and cut that part of the leaf off and most likely the plant will repair itself faster without that bad part. when you try and cut the leaf off at the node you will probibly never get as clear/clean node compared to pulling the leaf off